With the proliferation of electrically operated and controlled door systems has come the need for a low cost, easily installed, secure electric lock system.
For a specific instance, many garage doors are electrically operated, with the open/close commands coming from an attached radio control receiver, or a simple push button switch. These control devices provide control from, for instance, inside an automobile, or from inside the garage. Typically, no control is provided outside the garage. It is thus not possible to open the door from the outside of the garage. A push button similar to the one used for the inside control, of course, could be provided. The push button, however, gives access to anyone pressing it, and affords no physical security whatsoever. A properly designed key operated switch performs both of the functions of control and access limitation, but requires the operator to carry the proper key on their person, which is quite inconvenient. A combination lock, specifically an electronic combination lock, provides "keyless" control along with very high physical security. The basic objection to a full feature electronic lock in the past has been the system cost, installation cost and difficulty of installation.